iankelling.org Git - distro-setup/blob - btrbk-run

   1 #!/bin/bash
   2 # Copyright (C) 2016 Ian Kelling
   3
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at
   7
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16
  17 # todo: if we cancel in the middle of a btrfs send, then run again immediately, the received subvolume doesn't get a Received UUID: field, and we won't mount it. Need to figure out a solution that will fix this.
  18
  19 set -eE -o pipefail
  20 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  21
  22 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
  23
  24 usage() {
  25   cat <<'EOF'
  26 btrbk-run [OPTIONS]
  27 usually -t TARGET_HOST
  28 EOF
  29   echo "top of script file:"
  30   sed -n '1,/^[# ]*end command line/{p;b};q' "$0"
  31   exit $1
  32 }
  33
  34 script_dir=$(dirname $(readlink -f "$BASH_SOURCE"))
  35
  36 # note q is owned by root:1000
  37 # note p/m is owned 1000:1000 and chmod 700
  38
  39
  40 mountpoints=()
  41
  42 rsync_mountpoint=/q
  43
  44 # default options
  45 conf_only=false
  46 dry_run=false # mostly for testing
  47 rate_limit=no
  48 verbose=true
  49 if [[ $- == *i* ]]; then
  50   progress_arg="--progress"
  51 fi
  52
  53 default_args_file=/etc/btrbk-run.conf
  54 if [[ -s $default_args_file ]]; then
  55   set -- $(< $default_args_file) "$@"
  56 fi
  57
  58 temp=$(getopt -l help cl:m:npt:vh "$@") || usage 1
  59 eval set -- "$temp"
  60 while true; do
  61   case $1 in
  62     # only creates the config file, does not run btrbk
  63     -c) conf_only=true; shift ;;
  64     # bytes per second, suffix k m g
  65     -l) rate_limit=$2; shift 2 ;;
  66     # Comma separated mountpoints to backup. This has defaults set below.
  67     -m) IFS=, mountpoints=($2); unset IFS; shift 2 ;;
  68     -n) dry_run=true; dry_run_arg=-n; shift ;;
  69     -p) progress_arg="--progress"; shift ;;
  70     -q) verbose=false; verbose_arg=; progress_arg=; shift ;;
  71     # target hosts to send to. empty is valid for just doing local
  72     # snapshot. we have default hosts we will populate.
  73     -t) IFS=, targets=($2); unset IFS; shift 2 ;;
  74     -v) verbose=true; verbose_arg=-v; shift ;;
  75     -h|--help) usage ;;
  76     --) shift; break ;;
  77     *) echo "$0: Internal error!" ; exit 1 ;;
  78   esac
  79 done
  80
  81 # usefull commands are resume and archive
  82 cmd_arg=${1:-run}
  83
  84 if [[ -s $default_args_file ]]; then
  85   echo "$0: warning: default btrbk-run options set in $default_args_file (sleeping 5 seconds):"
  86   cat $default_args_file
  87   sleep 5
  88 fi
  89
  90 echo -e "$0: options: conf_only=$conf_only\ndry_run=$dry_run\nrate_limit=$rate_limit\nverbose=$verbose\ncmd_arg=$cmd_arg"
  91
  92 # set default targets
  93 if [[ ! -v targets ]]; then
  94   case $HOSTNAME in
  95     x2|kw)
  96       if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
  97         targets=($HOME_DOMAIN)
  98       fi
  99       ;;
 100     tp)
 101       targets=(frodo)
 102       if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 103         if timeout -s 9 10 ssh x2 :; then
 104           targets+=(x2)
 105         fi
 106       fi
 107       ;;
 108     frodo)
 109       targets=()
 110       ;;
 111     *)
 112       echo "$0: error: no default targets for this host, use -t"
 113       exit 1
 114       ;;
 115   esac
 116 fi
 117
 118 echo "targets: ${targets[*]}"
 119
 120
 121
 122 # set default mountpoints
 123 case $HOSTNAME in
 124   frodo)
 125     prospective_mps=(/i)
 126     ;;
 127   *)
 128     prospective_mps=(/a /q)
 129     if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 130       prospective_mps+=(/o)
 131     fi
 132     ;;
 133 esac
 134 case ${targets[0]} in
 135   kw|kww)
 136     prospective_mps=(/a)
 137     ;;
 138 esac
 139
 140 for mp in ${prospective_mps[@]}; do # default mountpoints to sync
 141   if [[ -e /nocow/btrfs-stale/$mp ]]; then
 142     echo "$0: warning: $mp stale, not adding to default mountpoints"
 143     continue
 144   fi
 145   if awk '{print $2}' /etc/fstab | grep -xF $mp &>/dev/null; then
 146     mountpoints+=($mp)
 147   fi
 148 done
 149
 150 echo "mountpoints: ${mountpoints[*]}"
 151
 152 ##### end command line parsing ########
 153
 154 rsync-dirs() {
 155   local host=$1
 156   local path=$2
 157   m rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
 158 }
 159
 160 vol-conf() {
 161   cat >>/etc/btrbk.conf <<EOF
 162 volume $vol
 163 EOF
 164 }
 165 sub-conf() {
 166   cat >>/etc/btrbk.conf <<EOF
 167 subvolume $sub
 168 EOF
 169 }
 170 tg-conf() {
 171   cat >>/etc/btrbk.conf <<EOF
 172 target send-receive ssh://$tg$vol/btrbk
 173 EOF
 174 }
 175 m() { printf "%s: %s\n" "${0##*/}" "$*";  "$@"; }
 176
 177
 178 if ! which btrbk &>/dev/null; then
 179   echo "$0: error: no btrbk binary found"
 180   exit 1
 181 fi
 182 # if our mountpoints are from stale snapshots,
 183 # it doesn't make sense to do a backup.
 184 check-subvol-stale ${mountpoints[@]} || exit 1
 185
 186
 187 cat >/etc/btrbk.conf <<EOF
 188 ssh_identity /root/.ssh/home
 189 # Just a guess that local7 is a good facility to pick.
 190 # It's a bit odd that the transaction log has to be logged to
 191 # a file or syslog, while other output is sent to std out.
 192 # The man does not mention a way for them to be together, but
 193 # I dunno if setting a log level like warn might also output
 194 # transaction info.
 195 transaction_syslog local7
 196
 197 # 20%ish speedup[]
 198 stream_buffer 512m
 199
 200 # so we only run one at a time
 201 lockfile                   /var/lock/btrbk.lock
 202
 203 # default format of short does not accomidate hourly preservation setting
 204 timestamp_format long-iso
 205
 206 # only make a snapshot if things have changed
 207 snapshot_create onchange
 208 # I could make this different from target_preserve,
 209 # if one disk had less space.
 210 # for now, keeping them equal.
 211 snapshot_preserve 36h 14d 8w 24m
 212 snapshot_preserve_min 4h
 213 snapshot_dir btrbk
 214
 215 # so, total backups = ~89
 216 target_preserve 36h 14d 8w 24m
 217 target_preserve_min 4h
 218
 219 # if something fails and it's not obvious, try doing
 220 # btrbk -l debug -v dryrun
 221
 222 rate_limit $rate_limit
 223 EOF
 224
 225
 226
 227 for tg in ${targets[@]}; do
 228   # for an initial run, btrbk requires the dir to exist.
 229   ssh root@$tg mkdir -p /mnt/root/btrbk
 230 done
 231
 232
 233
 234 for m in ${mountpoints[@]}; do
 235   # for /i, some special cases. there is just one static target and direction.
 236   if [[ $m == /i ]]; then
 237     vol=/mnt/iroot
 238     vol-conf
 239     sub=i
 240     sub-conf
 241     tg=frodo
 242     vol=/mnt/root
 243     tg-conf
 244   else
 245     vol=/mnt/root
 246     vol-conf
 247     sub=${m##*/}
 248     sub-conf
 249     for tg in ${targets[@]}; do
 250       tg-conf
 251     done
 252   fi
 253 done
 254
 255
 256 # todo: umount first to ensure we don't have any errors
 257 # todo: do some kill fuser stuff to make umount more reliable
 258
 259
 260 if $conf_only; then
 261   exit
 262 fi
 263
 264
 265
 266 if $dry_run; then
 267   m btrbk -v -n $cmd_arg
 268 elif [[ $cmd_arg == archive ]]; then
 269     for tg in ${targets[@]}; do
 270       m btrbk $verbose_arg $progress_arg $cmd_arg $vol ssh://$tg$vol
 271     done
 272 else
 273   # -q and just using the syslog option seemed nice,
 274   # but it doesn't show when a send has a parent and when it doesn't.
 275   m btrbk $verbose_arg $progress_arg $cmd_arg
 276 fi
 277
 278 # if we have it, sync to systems which don't
 279 if mountpoint $rsync_mountpoint >/dev/null; then
 280   for tg in ${targets[@]}; do
 281     case $tg in
 282       tp|li|lk)
 283         for x in /p/c/machine_specific/*.hosts; do
 284           if grep -qxF $tg $x; then
 285             dir=${x%.hosts}
 286             rsync-dirs $tg $dir
 287           fi
 288         done
 289         ;;
 290     esac
 291   done
 292 fi
 293
 294 if ! $dry_run; then
 295   m $script_dir/mount-latest-remote ${targets[@]}
 296 fi
 297
 298
 299 # todo: move variable data we don't care about backing up
 300 # to /nocow and symlink it.
 301
 302
 303 # background on btrbk timezones. with short/long, timestamps use local time.
 304 # for long, if your local time moves backwards, by moving timezones or
 305 # for an hour when daylight savings changes it, you will temporarily get
 306 # a more aggressive retention policy for the overlapping period, and
 307 # vice versa for the opposite timezone move. The alternative is using
 308 # long-iso, which puts timezone info into the timestamp, which means
 309 # that instead of shifting time, you shift the start of day/week/month
 310 # which is used for retention to your new local time, which means for
 311 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 312 # retention will be 8 hours more aggressive since midnight is at a new
 313 # time, unless you fake the timzeone using the TZ env variable.
 314 # However, in the short term, there will be no inconsistencies.
 315 # I don't see any problem with shifting when the day starts for
 316 # retention, so I'm using long-iso.
 317
 318 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z